• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.556-561
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• 2012

In this study, the effect of properties of gas diffusion layer (GDL) on the performance of polymer electrolyte membrane fuel cell (PEMFC) was investigated using the numerical simulation. The multi-phase mixture ($M^2$) model was used to calculate liquid water saturation and oxygen concentration in GDL. GDL properties, which were contact angle, porosity, gas permeability and thickness, were changed to investigate the effect of GDL properties on the performance of PEMFC. The results demonstrated that performance of PEMFC was increased with increasing contact angle and porosity of GDL, but decreased with increasing thickness of GDL. The liquid water saturation was decreased but oxygen concentration was increased at the GDL-catalyst layer interface, because the mass transfer resistance decreased as the porosity and contact angle increased. On the other hands, as the thickness of GDL increased, pathway for liquid water and oxygen gas became longer, and then mass transfer resistance increased. For this reason, performance of PEMFC decreased with increasing thickness of GDL.

• Polymer(Korea)
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• v.33 no.6
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• pp.525-529
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• 2009

In order to manufacture 2-layer flexible copper clad laminate (FCCL) s having the excellent performance high adhesion properties between copper foil and polyimide film are required. Silane coupling agents with specific functional groups as an adhesion promoter are generally used to enhance the adhesion. In our study, we synthesized a novel silane coupling agent for increasing the adhesive property between copper layer and polyimide layer. The surface morphology of rolled copper foil, as a function of the concentrations of the coated silane coupling agent, was fully characterized. As fabricated 2-layer FCCL, we observed that adhesive properties were changed by the surface morphology and we confirmed that the novel silane coupling agent affects adhesive properties in FCCL with two types of poly (amic acid)s.

• Polymer(Korea)
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• v.33 no.6
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• pp.520-524
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• 2009

The effects of oxidative degradation on the performance of crosslinked polyethylene pipes were analyzed by the investigation of tensile properties and chemical structure change of the pipes during oxidative degradation. Annealing at high temperatures or UV irradiation method was used to induce the oxidative degradation of the crosslinked polyethylene pipes and the effects of the die temperature on the oxidative degradation of the pipes were also investigated. The tensile properties and chemical structure change of the pipes were investigated by universal testing machine and FT-IR, respectively. With the progress of thermo-oxidative degradation the tensile strength of the pipes slowly decreased but the elongation at break rapidly decreased, and the chemical structure of the pipes also changed considerably because of the introduced oxygen molecules. These results would be useful in estimating the performance deterioration of the crosslinked polyethylene pipes due to the oxidative degradation during production and storage.

• Journal of the Korean Institute of Gas
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• v.2 no.3
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• pp.1-11
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• 1998

To increase peel strength, low temperature properties and flowability of pressure sensitive adhesives(PSA) used in a heat shrinkable sheet, these properties were evaluated by changing each components in type and content. In this study, Isobutylene-co-Isoprene Rubber (IIR) which has good wetherability was selected as a base polymer. Instead of rosin ester, petroleum resin was selected as a tackifier because of superior peel strength. By decreasing petroleum resin contents, flowability of PSA was decreased. High molecular weight of polybutene was better than low molecular weight for the peel strength of PSA. Large particle size of carbon black showed better properties than small one in peel strength and brittleness temperature. By adding calcium carbonate, the cost of compound was able to be reduced. But it must be used with carbon black.

• Elastomers and Composites
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• v.58 no.4
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• pp.161-172
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• 2023

Because particulate matter has emerged as a major contributor to air pollution, the tire industry has conducted studies to reduce particulate matters from tires by improving tire performance. In this study, we compared the conventional blending method, in which rubber, filler, and additives are mixed simultaneously, to the Y-blending method, in which masterbatches are blended. We manufactured carbon black (CB)-filled natural rubber (NR)/butadiene rubber (BR) blend and silica-filled epoxidized NR/BR blend compounds to compare the effects of the two blending methods on the physical properties of the compounds and the amount of particulate matter generated. The Y-blending method provided uniform filler distribution in the heterogeneous rubber matrix, improved processability, and exhibited low rolling resistance. This method also improved physical properties owing to the excellent filler-rubber interaction. The results obtained from measuring the generation of particulate matter indicated that, the Y-blending method reduced PM_2.5 particulate matter generation from the CB-filled and silica-filled compounds by 38% and 60%, and that of PM₁₀ by 29% and 67%, respectively. This confirmed the excellence of the Y-blending method regarding the physical properties of truck bus radial tire tread compounds and reduced particulate matter generated.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1601-1602
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• 2014

• KIEE International Transactions on Electrophysics and Applications
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• v.11C no.2
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• pp.28-31
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• 2001

• Carbon letters
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• v.28
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• pp.96-99
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• 2018

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.10a
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• pp.27-28
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• 2008

• Proceedings of the Korean Society of Rheology Conference
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• 2001.09a
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• pp.162.2-162
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• 2001